One of ordinary skill in the art understands that performing meticulous processes and procedures on a work piece requires accurate alignment when fixing such a work piece is necessary. Conventional vises as illustrated in FIG. 1 includes a main body 1 having a vise jaw 3 (a claw for clamping a work piece), a moving element 2 having a vise jaw which corresponds to the vise jaw 3 and a screw bar 5 for transport of the moving element back and forth.
Problematically, when mounting and fixing a work piece on such a vise, the vise jaw at the moving element may clamp a work piece 6 at a slant. This results in inaccurate fixation of a work piece when parallel clamping is required. Improper clamping is caused by the clearance between the female screw of the moving element and the male screw of the screw bar. This makes it difficult to correctly mount and fix a work piece just by clamping the moving element in one step.
A vise clamp operator must therefore inspect the alignment of a work piece by determining whether the vise jaw is flush with the outer surface of a work piece before final clamping with full force. The operator typically uses a hammer to strike at the head of the vise jaw to align a work piece with test plates placed underneath the work piece. Downward hammering of the work piece against the test plates ensures parallel alignment. Only after this laborious process can an operator apply final clamping.
Such manual adjustment greatly increases processing time per work piece. The inefficiency is particularly noticeable in a mass production system in which a number of work items of the same size with the same processing item and position are processed.
Therefore, there is an unmet need for an apparatus which significantly reduces the difficulty and time required for accurate clamping of a work piece in a vise.